No amount of shaking will initiate any NFC-type action. One NFC (near-field contact) chip needs to physically touch (or be very close) to another NFC chip to activate any actions (in this case, a payment).
You are correct though, that some newer credit/debit cards have that NFC chip built in. So when you wave the card next to (very close to – touching almost) an NFC payment terminal (square, toast, and now possibly down the road based on this article an iPhone – rumored, not definite…) it will allow the two to talk to each other.
